Traces Of Pesticides Found In Raw Water Samples

April 26, 1986|By John Mulliken, Tallahassee Bureau

TALLAHASSEE — Very small concentrations of several pesticides have been found in raw water samples from more than a dozen public utilities in Palm Beach County, the Florida Department of Environmental Regulation said on Friday.

The low concentration of six chemicals and one metal do not pose an immediate health threat, but DER officials plan to test the treated water at each site, and expand the ground water search for pesticides into the county`s coastal and Glades farming areas, according to DER`s Dave Vogel.

``We do not see any significant public health threat. There is no cause for alarm,`` Vogel said.

The results are the first phase of a three-part investigation ordered by the Florida Pesticide Review Council two years ago. The council, which received the report during the meeting on Friday in Gainesville, focused on Palm Beach County because of the proximity of the county`s farm areas to its urban water supplies.

The investigation of selected water supplies discovered no trace of the most dangerous and highly toxic pesticides used by area growers.

``Obviouisly we`ve found no EDB or TEMIK,`` said DER Secretary Victoria Tschinkel.

No more than two contaminants were found at any one public water wellfield. Low levels of chemicals also were found at a dozen private utilities, including six water supplies for agricultural interests in the Everglades Agricultural Area.

Among the public water supplies with positive results were Palm Beach County`s Systems (NU)1, (NU)3 and (NU)9; West Palm Beach; Lake Worth; Royal Palm Beach; Jupiter; the Village of Golf; Atlantis; Palm Springs; and three small towns on the shore of Lake Okeechobee: Pahokee, Belle Glade and South Bay.

The most serious discovery appeared to be the Village of Golf where DER found two chemicals, 1,2 dichloropropane and diuron. While the diuron finding was far below toxic levels, the other chemical finding was not conclusively below estimated safety margins.

The recommended guideline for 1,2 dichloropropane, which is used on some golf courses, is below .56 of 1 part per billion. The test method could not specificially measure fractions below one part per billion for the chemical, and the finding was listed as a trace. The pesticide 1,2 dichloropropane is the only suspected carcinogen of the contaminants found by the study.

At two southwest Palm Beach County utilities plants, only the metal copper was found, both well within safety levels. Copper was the only contaminant discovered for which regulatory standards exist. The safe level for drinking water is 1,000 parts per billion.

County Utility (NU)3, which is west of Delray Beach, showed a level of 4.3 ppb, while County Utility (NU)9, near U.S. 441 west of Boca Raton, produced a reading of 2.0 ppb.

Eugenia Carey, county utilities laboratory director, said minute traces of copper had been discovered in annual tests made by the utility. The utilities department tests for most heavy metals every three years, as required by law.

Annual tests are taken for a few selected metals, including copper and zinc, she said. The county has not been forced to shut down any water wells to pollution.

``The only wells we`ve lost were to the airport expansion,`` she said

Both copper and a pesticide known as Benomyl were found at County Utility (NU)1, but within safe levels. Benomyl is not on the list of 120 chemicals for which the state and federal government require routine testing in public drinking water, Carey said.

The same chemical was found in low levels at Jupiter and Royal Palm Beach.

In four surface water samples, the Clear Lake intake for West Palm Beach and intakes from Lake Okeechobee for Belle Glade, Pahokee and South Bay, the most common find was Atrazine, a herbicide that does not appear to be acutely toxic, according to government publications. It is used on sugarcane and corn.

With three exceptions, the findings were less than 1 ppb, well below the recommended guideline of 150 ppb. The exceptions were one reading of 1.8 ppb at South Bay and two readings, both of 8.7 ppb, at the Okeelanta Sugar Camp in the Everglades Agricultural Area.

The highest copper concentrations were in the mucklands of the Glades. A Florida Sugar Refinery sample measured 47 ppb, while a test at the Shelton Land and Cattle Co. produced a reading of 26 ppb.

Vogel said the water supplies studied for the report were selected because they represent ``worst case scenerios`` -- those water wells most likely to be affected by agricultural practices. The council selected a list of pesticides, while DER added additional general use pesticides believed to be heavily used in the county.

The DER`s Tschinkel said her department and the council would continue studying the pesticide problems, and attempt to determine if additional regulations are needed for any of the substances.

Vogel said the agency will begin to look at private wells in and around the actual farming areas for the second and third phases of the program.

``We hope to learn more about how certain chemicals behave in groundwater. If we can place some wells in the fields and some in adjacent areas, we can see if there is any off-site movement,`` he said.